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公开(公告)号：US5353310A
公开(公告)日：1994-10-04
申请号：US971380
申请日：1992-11-04
IPC分类号： H03H21/00 , H03H17/00 , H03H17/02 , H04B3/04 , H04B3/14 , H04L25/03 , H03D1/06 , H03D11/04 , H03K5/01 , H03K6/04 , H04B1/10 , H04L1/00 , H04L25/08
CPC分类号： H04L25/4975 , H04L25/03057 , H04L25/03343
摘要： For avoiding error propagation as a result of decision feedback equalization, the data to be transmitted are coded with a coder 2 which has a transfer function substantially inverse to the transfer function of the channel 4. Consequently, instantaneous decisions about the received symbol may be made at the receiver 6 without intersymbol interference causing a disturbance. If the channel transfer function differs from the transfer function of the precoder 2, intersymbol interference will again occur, so that the symbol error rate will increase. In order to restrict this increase of the symbol error rate as much as possible, the receiver comprises a cascaded circuit of an adaptive filter 18 which has an inverse transfer function to that of the channel and a decoder 21 which has an inverse transfer function to that of the precoder 2.
摘要翻译： 为了避免作为判决反馈均衡的结果的错误传播，要发送的数据用编码器2编码，编码器2具有与信道4的传递函数基本相反的传递函数。因此，可以对接收到的符号进行即时判定 在接收机6处没有造成干扰的符号间干扰。 如果信道传递函数与预编码器2的传递函数不同，则会发生符号间干扰，使得符号错误率将增加。 为了尽可能地限制符号错误率的这种增加，接收机包括自适应滤波器18的级联电路，其具有与信道的反向传递函数和具有与该信道相反的传递函数的解码器21 的预编码器2。
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2.发明授权Digital receiver with noise filter which also serves as a feedback filter providing intersymbol interference reduction 失效具有噪声滤波器的数字接收机，也可用作提供符号间干扰减少的反馈滤波器
公开(公告)号：US5761243A
公开(公告)日：1998-06-02
申请号：US642803
申请日：1996-05-03
CPC分类号： H04L25/03146
摘要： A receiver for transmitted signals which represent digital symbol values includes a low-pass filter to minimize transmission noise by reducing the receiver bandwidth. However, this creates pulse distortion which can cause intersymbol interference when the filtered signal is supplied to a symbol detector. Such interference is minimized by the inclusion of a feedback loop between the output of the symbol detector and the input to the filter, in which a detected symbol is multiplied by correction factor and supplied to a subtractor where it is subtracted from the signal to be filtered. The result of the subtraction is supplied to the filter. The noise reduction filter is thus also used for matching the intersymbol distortion characteristic of a filtered detected symbol to the intersymbol distortion characteristic of a filtered received signal pulse.
摘要翻译： 代表数字符号值的发送信号的接收机包括低通滤波器，以通过减少接收机带宽来最小化传输噪声。 然而，当滤波信号被提供给符号检测器时，这产生脉冲失真，这可能导致符号间干扰。 通过在符号检测器的输出和滤波器的输入之间包括反馈回路来最小化这种干扰，其中检测到的符号乘以校正因子，并将其提供给减法器，在该减法器中将其从要滤波的信号中减去 。 减法的结果被提供给过滤器。 因此，噪声降低滤波器也用于将滤波后的检测符号的符号间失真特性与已滤波的接收信号脉冲的码间失真特性相匹配。
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公开(公告)号：US5570396A
公开(公告)日：1996-10-29
申请号：US240041
申请日：1994-05-06
CPC分类号： H04L7/0062
摘要： In a digital symbol receiver it is necessary to generate a clock signal with a correct frequency and phase, so that decisions a.sub.k about the value of transmitted symbols a.sub.k can be made at the right detection instants. A simple method of obtaining the desired clock signal is to adjust a VCO by means of a control signal obtained from the correlation of a detection signal r(t) with the detected symbols a.sub.k filtered by a symbol filter. The symbol filter may comprise a cascade connection of a differentiator and a filter which has a transfer function which is an estimate of the transfer function of a channel which supplies the transmitted symbols.
摘要翻译： 在数字符号接收机中，必须产生具有正确频率和相位的时钟信号，从而可以在正确的检测时刻进行关于发送符号ak的值的判决+ E，cir a + EE k。 获得期望的时钟信号的简单方法是通过从检测信号r（t）与由符号滤波器滤波的检测符号+ E，cir a + EE k的相关性获得的控制信号来调整VCO。 符号滤波器可以包括微分器和滤波器的级联连接，滤波器具有作为提供发送符号的信道的传递函数的估计的传递函数。
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公开(公告)号：US5131011A
公开(公告)日：1992-07-14
申请号：US545308
申请日：1990-06-26
CPC分类号： H04L25/03337
摘要： Non-linear intersymbol interference and noise in a received data signal are corrected through use of a Viterbi detector which estimates the most likely sequence of transmitted data symbols by keeping track of candidate data sequence that are recursively updated, based on likelihood measures which are determined by a signal processor which includes circuits for estimating hypothesized channel outputs in the absence of noise. Non-linear input-output relations are stored in one or more look-up tables which, in a preferred embodiment, are registers that store hypothesized channel output symbols in the absence of noise. The contents of the look-up tables may be modified in response to an error signal representative of the difference of the channel output signal and the look-up table output signal.
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5.发明授权Method and device utilizing erasure information as a reliability indicator in an information medium 失效在信息介质中使用擦除信息作为可靠性指示符的方法和装置
公开(公告)号：US6134065A
公开(公告)日：2000-10-17
申请号：US709500
申请日：1996-09-06
CPC分类号： G11B20/182 , G11B27/36
摘要： A method and a device in which information is written on a medium and is read out, and which establishes whether the information read is sufficiently reliable, and in which so-called erasure information is used to establish the influence of media defects and other imperfections on the occurrence of errors in a transmission system. The medium is, for example, a hard disk containing one or more bad spots whose location can be accurately detected. The implementation of the method makes accurate and fast computation of the bit error rate possible.
摘要翻译： 一种方法和装置，其中信息被写在介质上并被读出，并确定读取的信息是否足够可靠，并且使用所谓的擦除信息来建立媒体缺陷和其他缺陷的影响 在传输系统中发生错误。 该介质例如是包含一个或多个可以准确检测位置的不良点的硬盘。 该方法的实现使得误码率的准确和快速计算成为可能。
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公开(公告)号：US5557638A
公开(公告)日：1996-09-17
申请号：US212669
申请日：1994-03-10
申请人： Kevin D. Fisher , Ho W. Wong-Lam , Johannes W. M. Bergmans , Frits A. Steenhof , Johannes O. Voorman
发明人： Kevin D. Fisher , Ho W. Wong-Lam , Johannes W. M. Bergmans , Frits A. Steenhof , Johannes O. Voorman
IPC分类号： H04L25/03 , H03K5/08 , H03M13/23 , H04L25/06 , H04L25/12 , H04L25/30 , H04L25/34 , H04L25/49
CPC分类号： H03K5/088 , H04L25/061 , H04L25/12
摘要： In a digital transmission system including a transmitter (2) coupled via a channel (4) to a receiver (6) a detection signal r.sub.k is compared with a number of reference values to determine the destination symbols a.sub.k. Since the size of the received signal r.sub.k is not known in advance, the ratio between the detection signal and the reference values is to be determined by an adapting circuit (16) on the basis of the received signal and the decisions made. The problem may then occur that as a result of an initially erroneous value of the ratio between detection signal and reference values not a correct adaptation is made. By recognizing such a situation because specific values of the symbols a.sub.k are lacking, in such a situation said ratio can be brought to such a value by the correction circuit (18) that all the values of a.sub.k again occur.
摘要翻译： 在包括经由信道（4）耦合到接收机（6）的发射机（2）的数字传输系统中，将检测信号rk与多个参考值进行比较，以确定目的地符号+ E，cir a + EE k。 由于接收信号rk的大小预先不知道，所以检测信号与参考值之间的比率将由适配电路（16）根据接收到的信号和作出的决定来确定。 然后可能出现这样的问题，即由于检测信号和参考值之间的比率的最初错误的值不是正确的适应。 通过识别这种情况，因为缺少符号+ E，cir a + EE k的特定值，在这种情况下，可以通过校正电路（18）使所述比值达到这样的值，即所有的+ E， 再次出现cir a + EE k。
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公开(公告)号：US5463654A
公开(公告)日：1995-10-31
申请号：US98673
申请日：1993-07-28
CPC分类号： H04L25/03006
摘要： In a data receiver (6) a detection means (10) is used for determining a symbol value from the received signal. For reducing the effect of cyclostationary noise signals, a number of simultaneously operating detectors (12, 14) are used which derive a sequence of symbols from the input signal sampled at different instants. On the basis of a reliability measure simultaneously derived by the detectors, the symbol sequence whose associated reliability measure expresses the greatest reliability is conveyed to the output of the receiver with the aid of selection means.
摘要翻译： 在数据接收器（6）中，检测装置（10）用于从接收信号确定符号值。 为了减少循环平稳噪声信号的影响，使用多个同时操作的检测器（12,14），其从不同时刻采样的输入信号中导出符号序列。 基于由检测器同时导出的可靠性度量，其可靠性测量表达最大可靠性的符号序列借助于选择装置被传送到接收器的输出。
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8.发明授权
公开(公告)号：US5311558A
公开(公告)日：1994-05-10
申请号：US848810
申请日：1992-03-10
CPC分类号： H04B3/23
摘要： For reducing the complexity of adaptive systems such as equalizers, echo cancellers and clock recovery systems, errors are often determined only once per n samples, where n is an integer. If the input signal of such an adaptive system comprises cyclostationary components, it may occur that the adaptive system does not converge to a desired value. By selecting n in such a way that the greatest common divisor of n and the cyclostationary period m of the input signal is equal to 1, convergence of the adaptive system is ensured.
摘要翻译： 为了降低诸如均衡器，回波消除器和时钟恢复系统之类的自适应系统的复杂性，通常每n个采样器只确定一次错误，其中n是一个整数。 如果这种自适应系统的输入信号包括循环平稳组件，则可能发生自适应系统不会收敛到期望值。 通过以n的最大公约数和输入信号的周期平稳周期m等于1的方式选择n，确保了适应系统的收敛。
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9.发明授权Data transmission system comprising a decision feedback equalizer and using partial-response techniques 失效数据传输系统包括判决反馈均衡器和部分响应技术
公开(公告)号：US4866736A
公开(公告)日：1989-09-12
申请号：US203655
申请日：1988-06-07
IPC分类号： H04B3/06 , H04L25/03 , H04L25/497
CPC分类号： H04L25/03057 , H04L25/066
摘要： A system for transmitting an n-level data signal (d.sub.k) at a given symbol rate 1/T comprises a data transmitter (1), a transmission channel (2) and a data receiver (3) with an equalizer (30) of the decision feedback type. By arranging this equalizer (30) for forming an estimate (c.sub.k) of a virtual m-level data signal (c.sub.k) instead of the output signal (b.sub.k) of the data transmitter (1) error propagation in the equalizer (30) is considerably reduced without thereby appreciably adding to the implementation-complexity of the system.
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公开(公告)号：US6091558A
公开(公告)日：2000-07-18
申请号：US909919
申请日：1997-08-12
CPC分类号： G11B20/10212
摘要： A device for write precompensation of data signals to be recorded on a magnetic medium, which device has an input for receiving input data signals and an output for supplying output signals to be recorded, an integrator/limiter circuit which receives the input data signals and which supplies an output signal which is in synchronism with the data signal and whose amplitude varies substantially linearly as a function of time at positions where a signal transition appears in the data signal, which amplitude is limited within a data symbol interval; an adjustable filter which receives the input signals and supplies an output signal whose instantaneous values depend on the pattern of preceding and future signal transitions in the data signal; and a comparator circuit which through comparison of the output signal of the integrator/limiter circuit and the output signal of the filter produces the output signal in which at least some signal transitions of the input data signal can be shifted in time. An important aspect of the present invention is that with the output signal dt an arbitrary number of desired time shifts can be obtained rather than that, as in the prior art, only a choice can be made from a limited number of delay values.
摘要翻译： 一种用于写入预记录在磁介质上的数据信号的装置，该装置具有用于接收输入数据信号的输入端和用于提供要记录的输出信号的输出端，接收输入数据信号的积分器/限幅电路，以及哪个 提供与数据信号同步的输出信号，其幅度随着数据信号中出现信号转变的位置处的时间的函数而基本线性变化，该幅度被限制在数据符号间隔内; 可调滤波器，其接收输入信号并提供其瞬时值取决于数据信号中的先前和未来信号转换的模式的输出信号; 并且通过比较积分器/限幅器电路的输出信号和滤波器的输出信号的比较器电路产生其中输入数据信号的至少一些信号转换可以及时移位的输出信号。 本发明的一个重要方面是，通过输出信号dt，可以获得任意数量的期望时间偏移，而不是象现有技术那样，只能从有限数量的延迟值中进行选择。
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